Pentagon plans to take money away from military construction projects to pay for President Trump’s border wall would potentially deal an outsize blow to Puerto Rico and particularly affect a program helping European allies deter Russia, according to a Washington Post analysis.

Under pressure from lawmakers, the Defense Department released a list Monday detailing $12.9 billion in military construction projects that had received money from Congress but had yet to be contracted. That status puts them in a pool of funding that Trump could take for the wall using emergency powers.

The Pentagon hasn’t said which specific projects would be defunded. But it has ruled out taking money from military housing projects or contracts due to award before the end of the fiscal year. When those are stripped out, the refined list decreases to $4.35 billion worth of projects that are actually vulnerable. The Trump administration plans to take up to $3.6 billion, or 83 percent, for the wall, meaning most of the projects on the shorter list could be defunded.

Puerto Rico is the most affected U.S. territory or state, with 10 projects at a value of $403 million on the smaller list, according to The Post’s analysis.

The projects in Puerto Rico that would potentially have their funding taken away include the construction of a school for military children on what was once Ramey Air Force Base and improvements to Camp Santiago, a training facility operated by the Puerto Rico National Guard.

Also on the most-vulnerable list is some $745 million worth of projects for the European Deterrence Initiative and its predecessor program. President Barack Obama launched the program in 2014 to shore up the defenses of European allies after Russia annexed Crimea from Ukraine.

The initiative is the bedrock of the Pentagon’s efforts to deter Russia from taking military actions in Europe against American allies, a mission at the heart of the national defense strategy that Defense Secretary Jim Mattis rolled out before his resignation in December.

The 23 European projects in the program at risk are aimed at making it easier for allied forces to respond to any Russian military actions in Europe, part of a broader effort to deter Moscow from armed aggression.

The initiatives at risk include a plan to build a facility for Special Operations forces and their training in Estonia; projects to construct ammunition and fuel storage facilities and staging areas in Poland; and planned upgrades to aircraft surveillance facilities in Italy and Britain, as well as airfield and fuel storage upgrades in Slovakia and Hungary.

A relatively obscure statute in the U.S. code governing the military known as Section 2808 allows the defense secretary, in the event of a national emergency requiring the use of troops, to tap military construction funds to build projects necessary to support those forces. The secretary can tap only funds not yet awarded under contract.

The Trump administration says the military construction projects that lose funding for the wall would be “backfilled” in the coming year’s budget, as long as Congress passes the request in full and on time, and therefore none of the projects ultimately would be delayed or scrapped. But Democrats in Congress have balked at the idea of appropriating money for construction projects they have already funded, setting up a political battle that could leave the projects in question frozen, delayed or scrapped.

One challenge the Pentagon faces in trying to take up to $3.6 billion from the military construction account is that the account is an agglomeration of many small projects costing tens of millions of dollars each across many states and countries. The vulnerable construction projects worth $4.35 billion are located in 31 states and 18 foreign nations.

Washington is the most affected state by amount of money, with three projects totaling $185 million at risk of losing funding, including a project at Naval Base Kitsap-Bangor that would expand the pier there to accommodate two additional Seawolf-class fast-attack submarines.

New York is the second-most-affected state by the amount of money at risk because of two sizable projects with $160 million in funding at the U.S. Military Academy at West Point. The academy is slated to get a new parking garage as well as a state-of the-art engineering center.

Virginia is the most affected state by number of projects potentially disrupted, with seven plans valued at $143 million, including construction to improve security at the Pentagon and a cyber operations facility at Joint Base Langley-Eustis. It is followed closely by Alaska, with five projects potentially affected at a value of $131 million.

More than 40 percent of the potentially impacted funding is going to international construction projects at facilities outside the United States, many of them American military facilities. Operations in Germany would be most affected, with 13 projects at a value of $513 million on the list. Operations in Japan are a close second, with 10 projects at a value of $490 million potentially affected.

The types of projects vary, but schools for the children of U.S. military personnel at home and abroad would be among the most impacted. Some $664 million in at-risk funding is money that was appropriated by Congress for the construction or renovation of elementary schools, high schools and middle schools. About $132 million of that funding is for two school projects that the Pentagon says have been canceled for unrelated reasons.

Within the Pentagon, the Air Force is by far the service that is most affected, with $1.31 billion worth of projects on the refined list. It’s followed by the Navy, with $786 million worth of projects, and the Army, with $680 billion.

Lawmakers and officials representing the areas with military construction projects potentially most at risk expressed anger and frustration on Thursday.

“President Trump promised that Mexico would pay for his wasteful wall, and now he wants taxpayers, Washington state families, and our national security priorities to pay the price,” Sen. Patty Murray (D-Wash.) said in a statement. “This is outrageous and I’m going to fight back with every tool at my disposal.”

Ramon Luis Nieves, a former state senator representing San Juan, said it was “very sad” that Puerto Rico was being targeted, even as it continues a slow recovery from Hurricane Maria that has been hampered by what many view as an inadequate response from the Trump administration and Congress.

“You cannot say you’re building a wall to protect national security in the continental U.S. while taking moneys away from the people of Puerto Rico and the preparedness of our troops who train here,” Nieves said.

Anger from lawmakers comes as internal frustration at the Pentagon over the border expenditures spills into public. In recent memos published by the Los Angeles Times on Thursday, Marine Corps Commandant Gen. Robert Neller warned that “unplanned and unbudgeted” items including the border operation, border security funding transfers and recovery costs related to Hurricanes Florence and Michael would divert money away from important military tasks. The net effect of those budgetary pressures, Neller wrote, pose an “unacceptable risk to Marine Corps readiness and solvency.”

In a statement, Lt. Col. Joe Buccino, a spokesman for acting defense secretary Patrick Shanahan, said the Pentagon was working with Congress on several proposals for funding hurricane repair. “With the support of and rapid action of Congress, we anticipate the Marine Corps will maintain its current high level of combat readiness,” he said.

The Pentagon’s refusal to publicly detail which military construction projects would be defunded to pay for Trump’s wall has angered lawmakers already upset about his decision to circumvent Congress by declaring a national emergency.

Lawmakers anticipate getting more precise details from the Pentagon in coming weeks, but Democrats say they have no intention of using their spending bills to “backfill” money for projects the Pentagon chooses to cancel.

“I will not support any backfill of funds diverted from military construction projects to pay for Trump’s wasteful wall,” said Rep. Debbie Wasserman Schultz (D-Fla.), who chairs the military construction and veterans affairs appropriations subcommittee in the House. She said the coming year’s bill “will not include replacement funding for any projects clawed back for this purpose.”

Republicans, however, insist that they will backfill the affected projects.

“Securing our southern border is of the utmost importance,” Sen. Richard C. Shelby (R-Ala.), chairman of the Appropriations Committee, said this week in a statement. “While no final decisions have been made regarding specific funds to be used for border projects, I will work with my colleagues to backfill any funding that may be diverted from military construction projects.”

That puts the Democrats who control the House on a collision course with the Senate Republican majority over the issue. How it ultimately shakes out will probably remain unclear for months, as lawmakers work toward a Sept. 30 deadline, when government funding will expire if they don’t pass new spending bills for the 2020 fiscal year. The threat of another shutdown will loom.

Numerous other issues will also be at play, including Trump’s demands for still more money for the border wall and the need to raise the federal government’s borrowing limit.

Sen. Martha McSally (R-Ariz.) claimed ahead of casting her vote in favor of Trump’s national emergency declaration last week that she had received commitments from the Pentagon that it would leave certain projects in Arizona untouched. But a project to build a ground transport equipment building at Arizona’s Fort Huachuca is on the most-vulnerable list.

“Fort Huachuca has a long overdue project from Fiscal Year 2018 that we are actively working to keep off any chopping block and will fight tooth and nail to backfill if needed,” Katie Waldman, a spokeswoman for McSally, said in a statement.

In addition to the possibility of using appropriations bills to limit the Trump administration’s authority going forward, Democrats have another powerful tool at their disposal in the conflict over the national emergency declaration: The National Emergencies Act allows them to bring up resolutions of disapproval every six months, potentially forcing Republicans to take another tough vote on the issue six months from now.

They are likely to exercise that ability, according to a senior Democratic aide who spoke on the condition of anonymity ahead of a public announcement, but no final decisions have been made and other issues will be considered including the disposition of any court cases.

The developments come as the House prepares to vote Tuesday to override Trump’s veto of Congress’s disapproval resolution that sought to overturn the president’s national emergency declaration. The vote is expected to fall short of the needed two-thirds majority but will give Democrats another opportunity to denounce Trump for what they call unconstitutional overreach. Most Republicans are likely to defend the president.